Influencing Factors of Fatigue Life of Nano-Silver Paste in Chip Interconnection

Abstract

The finite element software ANSYS was used to simulate the solder joints in the flip chip, and the stress and strain distribution results of the solder joints are displayed. During the simulation process, the final results of the simulation were not the same when the solder joints of different sizes were used. The simulation results under thermal cycling load show that the area where the maximum stress and strain occur is mostly distributed in the contact area between the solder joint and the copper pillar and at the solder joint. During the entire thermal cycling load process, the area where the maximum change in stress and strain occurs is always at the solder joint, and when the temperature changes, the temperature at the solder joint changes significantly. From the comprehensive analysis, the relevant empirical correction calculation equation is used to calculate and predict the thermal fatigue life of the solder joint. We found that when the diameter of the solder joint is constant, the increase in the height of the weld point will increase its thermal fatigue life; when the height of the weld point is constant, the increase in the diameter of the weld point increases its thermal fatigue life. The effect of height is greater than the effect of diameter.